This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Currently, the mechanisms linking motor decline and cognitive loss are poorly understood. To help overcome this problem, we are conducting a series of experiments using the rhesus monkey (Macaca mulatta), which like humans shows cognitive decline during aging. Moreover, it can be maintained under carefully controlled environmental conditions (e.g., diet, temperature, photoperiod, medication, and sex-steroid exposure). In this ongoing pilot study, we are assessing cognitive function using the delayed response test of spatial working memory, the delayed non-matching-to-sample test of recognition memory, and complex reaction time;we are also assessing motor speed with a simple reaction time task, fine motor function with food retrieval tasks, locomotor function with videotracking analysis of spontaneous and motivated locomotion, and circadian activity and sleep quality indices with continuous home cage monitoring. These measurements enable us to test the hypotheses that age-associated motor decline and circadian rhythm disruption are closely correlated with concurrent age-associated cognitive decline. This pilot study represents a rapid and cost-effective way of establishing whether the rhesus monkey can act as a pragmatic animal model for future mechanistic studies and for the development of treatment strategies. Moreover, the data will be valuable to our clinical collaborators at OHSU, who are planning the development and implementation of related human studies, and to other investigators who are studying human cognitive aging.